Tanzanite: Gemstone and Jewelry


Tanzanite is a distinct and rare gemstone found in Tanzania, East Africa. It's famous for its deep blue color and unique trichroism qualities, which make it appear brilliant and sometimes purple. Tanzanite was discovered over half a century ago by Maasai tribesmen who wandered in the Merelani hills of Northern Tanzania in search of food.

The gemstone was introduced to the international market in the 1960s. From then on, it has become a sought-after precious gemstone and a popular material used in jewelry. This article seeks to explore the origin, history, physical properties, and uses of Tanzanite in the jewelry industry. Additionally, we'll highlight essential factors to consider when purchasing Tanzanite and its impact on the local economy.


Origin and Discovery: 

Tanzanite is named after its country of origin, Tanzania, a country found in East Africa. In 1967, a local Maasai tribesman named Ali Juuyawatu discovered the gemstone in the Merelani hills of Northern Tanzania. It is believed that the discovery of Tanzanite was accidental- the Maasai herder was in search of water when he stumbled upon rough stones with a blue hue in a dried-up riverbed.

Upon closer inspection, he thought they were sapphires and took some of the rocks to a nearby trader, Manuel de Souza. Manuel was a well-known gemstone wholesaler, trader, and traveler. He was passing through Arusha, a town in Northern Tanzania, when he was approached by Ali. The Maasai herder showed Manuel the blue stones, but he was not sure what they were. Manuel immediately recognized that they were unique and took an interest in them. He then took the rocks to Nairobi for Identification.

After some tests, it was discovered that the blue stones were a never-seen-before mineral. The samples were then sent to the Gemological Institute of America (GIA), where they were studied in-depth. It was discovered that the new crystal was a variety of the mineral zoisite, containing traces of Vanadium and Chromium. This chemical reaction is responsible for the distinct blue and purple hue in the crystal. The gemstone was then named Tanzanite by Tiffany & Co., a New York-based jewelry company that was one of the first to introduce the gemstone to the international market.


Physical Properties: 

Tanzanite is a Hydrous Calcium Aluminium Silicate mineral belonging to the Epidote group. The gemstone is made of calcium, aluminum, oxygen, silicon, and hydroxyl ions. Additionally, it contains traces of the minerals vanadium and chromium, which are responsible for the distinct blue and violet hue seen in the stone. The gemstone has a hardness of 6.5-7 on the Mohs scale of mineral hardness and a specific gravity of 3.10-3.38.

Tanzanite has excellent cleavage in one direction, which makes it susceptible to breakage or scratches if not handled with care. The crystal structure of Tanzanite is orthorhombic, and it's formed in a prismatic crystal with a flat top. Its color comes from the selective absorption of light due to the presence of Vanadium and Chromium.

A Tanzanite crystal may exhibit trichroic properties when observed under polarizing light. This characteristic means that it appears different colors when viewed from different angles. It can appear blue, violet, or brownish-yellow in various lighting conditions. Tanzanite is found in a range of sizes and can be cut into different shapes, which include oval, round, cushion, and square. The size and quality of Tanzanite also affect its value. Large, high-quality Tanzanite stones are rare and more valuable than smaller or lesser quality stones.


Uses of Tanzanite in Jewelry: 

Tanzanite is a versatile and popular gemstone, and it's widely used in jewelry. The gemstone is often used as a center stone in engagement rings, pendants, earrings, and bracelets. It's also commonly used in combination with diamonds, giving a unique and elegant look to jewelry. Tanzanite is a birthstone for December, making it an excellent choice for December birthday gifts. The blue and violet hues of Tanzanite combine well with white gold and yellow gold, depending on the desired look.

It's a commonly used gemstone in various jewelry designs, from vintage to contemporary. The unique color and rarity of Tanzanite also add value to the jewelry piece. Tanzanite also has metaphysical and healing properties. It's believed to promote calmness, clarity, and wisdom, making it a favorite of healers and gemstone enthusiasts.


Tanzanite Grading: 

Gemstones are graded based on the 4Cs- color, clarity, cut, and carat weight, similar to diamonds. Tanzanite grading is based on the intensity of its color, with the most valuable being a deep blue or violet color. Clarity is also a significant factor, with the best quality being free of inclusions visible without a magnifying glass.

Inclusions can affect the durability and beauty of the gemstone. The cut of Tanzanite also affects its beauty and value. The cut should be precise, with excellent symmetry and proper proportions to maximize the gemstone's color and sparkle. The carat weight of Tanzanite also affects its value. Large, high-quality Tanzanite stones are rare and more valuable.


Factors to Consider When Purchasing Tanzanite: 

When purchasing Tanzanite, there are essential factors to consider to ensure that you get the best value for your money. Below are some of these factors:

  1. Color: The most critical factor to consider when purchasing Tanzanite is color. The most valuable are deep blue or violet colors, with no visible hints of brown or yellow. The color intensity should also be consistent throughout the stone.
  1. Clarity: The clarity of a Tanzanite stone is also crucial. The stone should be free of visible inclusions without magnification, as these can affect the durability and beauty of the gemstone.
  1. Cut: Tanzanite should have excellent symmetry, proper proportions, and precise cutting to maximize its color and sparkle.
  1. Carat Weight: The carat weight of Tanzanite affects its value. Large, high-quality stones are rare and more valuable.
  1. Treatment: Tanzanite is often heated to enhance its color. The heating process is a common practice among Tanzanite sellers. However, it's important to ensure that the heating process is done correctly and does not affect the durability or natural properties of the stone. It's advisable to purchase Tanzanite from a reputable dealer who provides certification of the stone's authenticity and treatment history.


Tanzanite and the Local Economy: 

Tanzanite mining has had a significant impact on the local economy in Tanzania. The Merelani hills, where Tanzanite is found, is a poverty-stricken region with few employment opportunities. The discovery of Tanzanite has created jobs for locals, from miners to traders, cutters, and polishers. Tanzania's government has recognized the importance of Tanzanite mining to the local economy and enacted laws and policies to regulate the mining and trade of Tanzanite.

Today, only Tanzanite mining companies that meet the set standards by the Tanzanian government are allowed to operate. Additionally, tax revenue from Tanzanite mining is a significant source of income for the Tanzanian government. However, Tanzanite mining is not without challenges.

The sector has been faced with issues such as smuggling, exploitation of miners, and illegal mining, which affect the sustainability of the industry. It's essential to ensure that Tanzanite is ethically mined and traded to safeguard the interests of the local communities and sustain the industry's growth.



Tanzanite is a rare and unique gemstone that has gained popularity in the jewelry industry due to its deep blue and violet hue and metaphysical properties. Its origin, physical properties, uses in the jewelry industry, and grading factors should be taken into consideration when purchasing Tanzanite. Additionally, the impact of Tanzanite mining on the local economy in Tanzania should also be considered, and it's important to promote ethical mining and trade practices to ensure sustainability and fairness in the industry. Tanzanite's rarity and beauty make it a valuable and cherished gemstone, appreciated by jewelry enthusiasts and collectors worldwide.

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